The present invention relates to an excitation stage of a transmission tube for short-wave transmitters. It can be applied notably to the making of single sideband RF transmitters.
In the prior art, high-power RF short-wave transmitters include at least two RF tubes, a very-high-power final tube for power values of over 100 Kw for example and also an excitation tube for use at a power of some Kw. The value of this arrangement is that the excitation tube enables the transmitter to stand up fairly well to voltage pulses of some Kvolts that appear during the short-circuits, which develop for very short intervals of the order of 500 nanoseconds, between the electrodes, namely the anode and the grid or the screen and the grid, of the transmission tube. However, when a malfunction of the excitation tube occurs because of this phenomenon, this arrangement, due to the substantial bulk of this type of installation, makes it almost impossible for the maintenance teams entrusted with replacing the malfunctioning excitation stage to act swiftly, and raises a problem of operation for the transmitter station since the working of the transmitter is interrupted for several hours: this entails a very heavy economic burden, given the high costs per hour of running RF transmitters.
The aim of the invention is to overcome the above-mentioned drawbacks.